Various studies on lactic acid bacteria or physiological effects of food products using lactic acid bacteria have been made since Metschnikoff's longevity theory.
As a function of lactic acid bacteria contained in fermented milk such as yogurt, for example, intestinal microflora improving effect, intestinal controlling action, etc. are well known. Recently, it has been reported that lactic acid bacteria have various functions such as immune activation action, antimicrobial action, antitumor action and the like. As described above, since various health effects are expected for lactic acid bacteria, fermented milk and lactic acid bacteria beverage using strains such as Lactobacillus acidophilus, Lactobacillus casei and genus Bifidobacterium, which are also detected in the human bowel, are put on the market.
By the way, active oxygen is important as a biological protection factor such as bactericidal action of leukocytes, but it becomes apparent that the excessive production of active oxygen in the living body causes various tissue disorders.
As the ordinary factor for generating active oxygen, there have been known stresses, alcohols, peroxides, drugs, exercises and the like. It is pointed out that active oxygen and lipoperoxide generated by these factors are closely connected with cerebral nerve diseases, circulatory diseases, cancers, alimentary diseases, hepatic diseases, arterial sclerosis, renal diseases, diabetes, aging and the like.
The living body retains a series of oxidation protection systems so to protect itself against oxygen toxicity. On the other hand, in order to permit these systems to function normally, it is important to ingest oxidation nutrient components sufficiently. As the natural oxidation nutrient components, there have been known vitamin E, vitamin C, .beta.-carotene, polyphenol and trace elements (e.g. selenium, copper, zinc, etc.). For the purpose of affording an antioxidation action, food products containing these nutrient components have been developed.
In vivo antioxidation mechanism is classified roughly into a preventive antioxidation action (controlling the generation of a radical) and a linkage-breakage type antioxidation action (scavenging and eliminating a radical which has already been generated) according to its action. Examples of those which have the former action include enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and the like. Examples of those which have the latter action include the above antioxidation nutrient components.
However, in a conventional food product, there have never been known products which aim at conducting linkage-elimination of superoxide (O.sub.2.sup.-) and hydrogen peroxide (H.sub.2 O.sub.2) which is connected with the lipid peroxidation.
It is an object of the present invention to provide an antioxidation food product, an antioxidation preparation and an antioxidation method for the linkage-elimination of superoxide and hydrogen peroxide, which express a superoxide dismutase (hereinafter referred to as "SOD")-like activity and a catalase (hereinafter referred to as "CAT") activity, simultaneously, and which are particularly superior in preventive antioxidation action.